The Defence Secretary has insisted that there is “no cover up” as Kenyan police look to reopen a probe into what happened to a woman whose body was found in a septic tank close to a British army base.

Ben Wallace said the Ministry of Defence (MoD) had aided the investigation into Agnes Wanjiru’s alleged killing after a soldier, according to reports, confessed to the sex worker’s murder.

Speaking to the House Magazine, the Cabinet minister said: “It’s a deeply concerning murder and story and there is no one in the MoD standing in the way of (an investigation).

“There’s no cover up, there’s no blockade.”

During the interview, the former Scots Guard revealed that when he was serving in Belize in the 1990s, there was a brothel situated at the back gate of the base.

He said it was no longer there but admitted that the armed forces had been guilty of turning a “blind eye” to the use of prostitutes among troops, particularly when serving in “countries in poverty”.

Police in Kenya earlier this month confirmed they are reopening Ms Wanjiru’s case.

The body of the 21-year-old was found at the Lions Court Hotel in the town of Nanyuki two months after she disappeared in March 2012.

According to the Sunday Times, a soldier has allegedly confessed to the killing, and another soldier reported it to senior officers at the time – but no action was taken.

In a report last month, the newspaper said that a soldier accused of the murder had been named by his comrades.

The town is close to the Batuk (British Army Training Unit Kenya) camp.

An initial inquiry was unsuccessful, but a fresh investigation has been launched after an inquest, delayed until 2019, found Ms Wanjiru was unlawfully killed.

A post-mortem examination found Ms Wanjiru died as a result of stab wounds to her chest and abdomen.

There was also evidence she had been beaten, although due to the condition of her body it was unclear whether she had been sexually assaulted.

Witnesses told the Sunday Times that Ms Wanjiru was last seen leaving the hotel’s bar with a British soldier.

The Defence Secretary told the House Magazine he heard of the case only when it was reported on by the Sunday paper.

The Conservative politician said the MoD stood ready to help but that, due to the 2006 Armed Forces Act, cannot conduct its own parallel investigation.

He said his department had shared names with the Kenyan authorities nine years ago but did not receive a mutual legal assistance request for help.