The company says some staff face dismissal

An investigation by ITV1's Tonight with Trevor McDonald found security staff sleeping while on duty and poor passenger searches.

The inquiry looked at the work of ICTS UK, one of the security firms used by Birmingham International Airport (BIA).

The firm's airport station manager has also been replaced.

BIA said the allegations related solely to ICTS UK.

Testing programme

In a statement, ICTS said 16 staff had been suspended and faced disciplinary action with "dismissal a potential outcome".

The company's station manager at BIA had been replaced and 30 staff, including "highly-experienced supervisors, trainers, auditors and agents" had been brought in from other airports, the statement added.

It will also bring in a new drug and alcohol testing programme for all ICTS employees at Birmingham, which will be extended to all UK and European employees.

ICTS UK said it was the first security company to implement such a programme.

The six-month investigation led by a whistleblower ICTS employee found planes left unguarded, poor staffing levels and luggage sent for extra checks ignored by officials.

One ICTS employee even boasted about landing his job despite having criminal convictions for grievous bodily harm and drink driving.

The programme, aired on Monday evening, showed one US Congress security expert call for flights from the airport to the US to be grounded after watching the footage.

The airport authority has sought to reassure passengers that its operations remain safe and meet all government security requirements.