Long-term sickness absence — conventionally defined as a continuous absence of four weeks or more — presents employers with a distinctive set of challenges. The legal protections around long-term absence are more extensive than those around short-term sickness. The potential for a condition to be a disability under the Equality Act 2010 is higher and must be actively considered. And the emotional and relational complexity of managing an employee who has been absent for an extended period makes the subject one that many managers avoid addressing with the rigour it requires.
These challenges are real, and this article does not minimise them. But they do not eliminate the employer’s right to investigate where there is genuine reason to question whether the absence is as described. A long-term absence that has been extended by misrepresentation, during which the employee is working elsewhere or engaged in activities incompatible with their reported incapacity, is a fraud against the employer regardless of the duration of the absence.
Understanding Long-Term Absence
Long-term absence is managed through a combination of statutory obligations and organisational policy. After seven days, the employee requires a fit note from a GP. For most employers, Statutory Sick Pay applies for up to 28 weeks. Company sick pay schemes, where they exist, may extend payment beyond this period. The employer’s obligation to maintain the employment relationship, to make reasonable adjustments where a disability is involved, and to follow a fair process before making any decision to dismiss, applies throughout.
An occupational health referral is typically part of the long-term absence management process. The occupational health assessment provides an independent medical view of the employee’s condition, their likely return date, and whether adjustments or a phased return are appropriate. It does not, however, address the question of whether the employee’s reported condition is genuine — that question is precisely the one that a private investigation is designed to answer where credible concerns exist.
Legitimate vs Suspicious Cases
The majority of long-term absences are genuine. This must be the starting point for any assessment. Mental health conditions, serious physical illness, complex musculoskeletal complaints, and recovery from surgical procedures are all legitimate reasons for extended absence, and the employee who is genuinely suffering has both legal protection and a reasonable expectation of being treated with care and dignity.
Suspicion of abuse is warranted where specific observable indicators suggest that the employee’s actual activities during the absence are inconsistent with the reported incapacity. A back condition that prevents attendance at work is not inconsistent with moderate daily activity; it may be entirely consistent with a photograph on a beach. A stress and anxiety diagnosis is not inconsistent with socialising, but it may be difficult to reconcile with full-time employment elsewhere or with managing a business. The investigation’s role is to establish what the employee is actually doing, not to second-guess the medical diagnosis.
Warning Signs
The employee’s social media presence during the absence shows physical activity, travel, or social engagement inconsistent with their reported condition and the restrictions described in their fit note or occupational health report.
The employee is known or suspected to be working for another employer or operating their own business during the absence period. This is a particularly significant indicator where the work involves physical demands or stress that is claimed to be the reason for the absence.
The reported condition changes or escalates over time in a way that is difficult to reconcile clinically — for example, a condition that begins as a short-term physical complaint and then transitions into a stress or mental health claim as the physical complaint becomes more scrutinised.
The employee’s engagement with the return-to-work process is obstructive or evasive: repeatedly cancelling occupational health appointments, failing to engage with phased return proposals, or providing updated fit notes without any change in the reported condition despite the passage of significant time.
A colleague or other source reports having seen the employee engaged in activities incompatible with their reported condition.
Evidence Gathering
Evidence gathering in a long-term sick leave investigation must be structured, documented, and conducted within the applicable legal framework. The investigative tools most appropriate to long-term absence cases are:
Covert surveillance: observation of the employee during the absence period to establish their actual activities. Where the absence is on the grounds of a physical condition, footage of the employee performing physical activities incompatible with that condition is highly probative. Where the absence is on mental health grounds, the evidential picture is more nuanced and requires careful interpretation.
Social media investigation: a systematic review of the employee’s publicly available social media presence during the absence period. Photographs, check-ins, event attendance, and other publicly available posts can establish a pattern of activity during the absence that is inconsistent with the reported condition.
Corporate and Companies House investigation: where the concern is that the employee is working or operating a business during the absence, a corporate investigation to identify business interests, director positions, or trading activity provides documentary evidence that can be corroborated by observation.
Employment investigation: where the employee is suspected of working for another employer, investigation through job boards, professional networking platforms, and direct enquiry can establish the existence of alternative employment during the absence period.
Investigation Methods
The investigation approach in a long-term sick leave case depends on the nature of the reported condition and the specific concern that has been identified. A physical condition that prevents work but where the employee is observed engaged in physical activities incompatible with that condition calls primarily for surveillance evidence. A suspected case of alternative employment calls primarily for corporate and employment intelligence. A social media-based concern calls for open source evidence gathering and, where surveillance corroborates it, a combination of both.
In all cases, the investigation should be conducted covertly until sufficient evidence has been gathered to put the matter to the employee in a formal investigative interview. A premature disclosure that an investigation is underway gives the employee the opportunity to adjust their behaviour and limit the evidence available.
Employer Responsibilities
Throughout any sickness investigation, the employer’s obligations under employment law remain in force. The employee must not be subjected to detriment for exercising their right to sick leave if they are genuinely ill. Where the condition may be a disability under the Equality Act 2010, the employer’s duty to make reasonable adjustments applies and must be considered alongside any investigation findings. And if the investigation produces sufficient evidence of fraud to justify disciplinary action, the employer must follow a fair process — the ACAS Code of Practice on Disciplinary and Grievance Procedures applies in full.
The investigation findings, however strong, do not replace the disciplinary process. They provide the evidential foundation for it. The employee must be informed of the allegation, given a genuine opportunity to respond, offered accompaniment at any formal hearing, and informed of their right to appeal. An employer who bypasses these requirements because the investigation evidence is compelling has misunderstood the framework within which disciplinary action is taken.
Concerned about long-term sickness absence abuse? Contact iSpy Detectives for expert employee sickness investigation support.