A trusted book-keeper who stole a million pounds from his dying boss was jailed for four and a half years on Monday.

Andrew Nyman, 51, took financial control of Watford firm Electro Replacement Limited (ERL), in Tolpits Lane, when the owner Peter Schonthal became bedridden with cancer and multiple sclerosis.

Mr Schonthal died last year at the age of 71, after the full extent of Nyman's theft had been uncovered.

His wife Linda had to abandon retirement plans to keep the firm afloat, St Albans crown court heard.

In a victim personal statement he had written before his death, Mr Schonthal said he had built ERL up over 40 years. Nyman's actions had left him feeling "sick and humiliated" and added to the stress of his terminal condition.

Mrs Schonthal, 68, said she had to go to work to rescue the business. She said they had suffered "deceit and betrayal" and that her husband felt he had let her down. "He was always apologising for losing so much."

She went on: "He trusted someone who took advantage of him. Peter thought Andrew was the son he never had."

Nyman, of Kensington Way, Borehamwood, pleaded guilty to charges of fraud, theft and false accounting.

Prosecutor Ann Evans said Nyman took more than £1.2 million during a 3 year period. "He either transferred money directly to his bank, withdrew it in cash, or transferred it to other bank accounts for his benefit.

"He also created fraudulent invoices and fake bank letters in order to disguise the theft of monies."

She said that some funds were transferred back to ERL by Nyman - making the net loss to the company of over 950,000.

Nyman, who had started working for the firm as a part time book-keeper, was gradually given more responsibility .

"In 2008, Peter Schonthal became unable to manage his affairs. He had developed a close relationship with the defendant over the years of his employment and trusted him with full access to his bank accounts, giving him personal details and security codes so that he could take over the day to day running of his own affairs, as well as those of ERL," she said.

Mrs Schonthal managed the company while he had control of the personal and business bank accounts.

The company was "cash rich" but problems were first noticed in 2011 when Orbis, one of the company's largest suppliers, had not received a payment of more than £100,000. Nyman produced a letter to Mrs Schonthal, purporting to be from Barclays Bank, apologising for the delay in payment. The letter was a forgery.

In October that year Nyman confessed to Mrs Schonthal that he had stolen more than a quarter of a million pounds. His brother Julian offered to reimburse ERL as much as he could, which was between £190,000 and £200,000. The couple accepted the amount and agreed not to take the matter further.

But when ERL's accountants carried out a full audit, they discovered much more had been taken.

Mrs Evans said Mrs Schonthal then instructed private detectives to try to locate the money. They spoke to Nyman who said he had been the victim of an internet scam. He said there was no money left and that he had sent it all to Dubai.

The police were informed in September 2013 after other attempts to repay the company had failed.

Colin Wells, defending, said Nyman had been divorced and bankrupted as a result of the case. He said the defence case was that £460,000 had been repaid. A confiscation hearing will be at a later date.

Jailing him, Judge Martin Griffith said: "These offences had a serious detrimental effect financially and emotionally. Mr Schonthal's last, bed-ridden years should not have been clouded by the feeling he had let down his wife."