Conditions inside Lewes Prison could be driving inmates to suicide, an independent watchdog has claimed.

Two people have taken their lives at the Victorian prison in the past two weeks, compared with three suicides in 2001 and one in the whole of 2000.

The trend has caused the Board of Prison Visitors, which monitors all aspects of prison life, to write to prisons minister Beverley Hughes.

The watchdog is urging the Prison Service to ensure money set aside for improvements to conditions in the fortress-like prison, built in 1853, is not spent elsewhere.

Board chairman Jane King said overhead pipes in cells and bars in the windows being were used as makeshift gallows by inmates intent on suicide.

In a damning report published last year the group said "appalling" living conditions contributed to depression, pushing some inmates over the edge.

On Sunday, Charles Wolfe, 28, of Bishop Lane, Henfield, was found hanging from a knotted bed sheet.

Wolfe, on remand facing charges of manslaughter and wounding following an alleged raid on a post office in Billingshurst, died the next day at the Royal Sussex County Hospital in Brighton.

A week earlier Nariman Tahamasbi, 27, was found hanging in his cell.

Tahamasbi, who was serving six months for fraud and deception, was taken to the Royal Sussex Hospital but died at 6.30pm on February 25.

MP Norman Baker said he was meeting prison governors in response to the two latest deaths.

He said: "It's obviously an issue of great concern and I will be speaking to the governor very soon.

"It's important to establish the reasons for these figures. It could be that there's a shortage of staff, meaning they are unable to supervise at-risk prisoners, or it could be the physical conditions in which they are being kept."

In January last year Home Secretary David Blunkett was called on by a coroner to investigate how prisoners on suicide watch were cared for following the death in custody of serial sex attacker Rashid Kausmally , 48, of Bear Road, Brighton, while on remand.

At the time John Wilson, deputy governor at the prison, said procedures had been reviewed and changes made in light of his case.

But in May Robert Vowles, a 37-year-old decorator hanged himself in prison awaiting trial for beating and stabbing a chef.

Mrs King said: "The refurbishment of the prison is essential to prevent further loss of life."

The prison governor has instructed his staff to refer all inquiries to the Prison Service in London.

A spokesman said: "The Prison Service investigates every death in custody so see what lessons can be learned and if there are steps which could be taken to avoid these events."