The Army's top bomb disposal officer resigned after expressing concerns about the pressures on his team operating in Afghanistan, it was disclosed.

The Ministry of Defence confirmed that Colonel Bob Seddon quit as principal ammunition technical officer of the Royal Logistics Corps.

In a BBC Panorama documentary to be broadcast tonight, Col Seddon suggested that he needed more operatives on the ground and raised fears over the psychological impact of the job.

The programme is authored by the widow of Staff Sergeant Olaf 'Oz' Schmid, who was based at Vauxhall Barracks in Didcot snf died in October last year while attempting to diffuse an improvised explosive device (IED).

Staff Sgt Schmid was one of four bomb disposal experts to be killed in Afghanistan in little over a year.

In his interview for the programme, Col Seddon said the Army was looking to bring more people into IED disposal teams but added that the measures would take "some time".

He said: "I am very concerned as their head of trade at the pressures that they are facing in Afghanistan.

"We are seeking now to bring people back into high threat IED operations that have been out for some time.

"We are looking at more senior officers becoming involved in this. We've broadened our training and selection but it will take some time before these measures can come into play.

"And what it does mean is, it means the existing cohort are going to be under pressure."

Col Seddon added that he thought the British Army "could do with more high threat teams and IED operators in Afghanistan".

The documentary reveals that the MoD suspended bomb squad recruitment in 2002 for 18 months, resulting in a severe shortage of operatives to deal with the huge numbers of IEDs in Iraq and Afghanistan.

Mrs Schmid airs her belief during the programme that fatigue may have played a part in her husband's death.

"He was flaking at that point, saying 'I do need a break from this. I need to step back because I need to recharge' and I don't feel that he necessarily had that time."

Panorama: A Very British Hero will air on BBC One at 8.30pm.