A father took on the Child Support Agency (CSA) and won by successfully challenging a £16,000 demand when a computer error left him unaware of the claim for nearly 15 years.

Colin Roberts, 52, a golf professional from Abernethy in Perthshire, said the CSA left him and his second wife "stressed and frightened".

The bill was suddenly presented to Mr Roberts in October regarding the child maintenance of his daughter, now aged 27. She was born during his first marriage, which broke down in 1986 when his former wife left the country.

While the CSA was alerted that there might be a claim against him in 1993, the authority did not track down Mr Roberts to make an application for earnings - instead surprising him with a demand for the accumulated bill of £16,000 last November.

Mr Roberts, who has been married to his second wife Paulette for nine years, said: "When the letter suddenly dropped through the door, we were frightened. We were expecting the officials to come to the door. Every time somebody knocked for us we thought, is this it?'.

"They way it was handled by the CSA was so cold, so unemotional. It was the first I had ever heard from them and it was treated as just a matter of course for them.

"The stress that it caused for myself and Paulette was immense. We were looking into what we could sell, looking at what meagre savings we had.

"We were so low. I said to Paulette, it is just not fair, I have to fight this'."

Mr Roberts has not seen his daughter since she was three years old, after her mother moved to Spain and he failed to win a court order to allow him to bring her up himself.

As far as he was concerned, he had done what he could to express his wish of taking care of his child and was devastated that the life which he had been forced to lay to rest had been revived. He said: "When I lost the court case, it was very hard. I was broken for many years. I basically had to accept in the end that I was never going to see Charlotte again."

Mr Roberts said that before he and his first wife separated in the early 1980s, he had given her a savings plan which at the time was worth £2000.

Additional maintenance payments had not be discussed, he said.

An automatic investigation can be triggered at the CSA if the mother applied for income support, or if the mother approaches the organisation directly with a claim of missing child maintenance money.

While Mr Roberts may have been liable to pay for upkeep of his child, it would have been a fraction of the £16,000 demand had the correct process been followed at the CSA. But because the CSA failed to properly trigger the claim, he is no longer liable.

Representing Mr Roberts was child and family law specialist John Fotheringham.

He said: "A lot of men buckle when this happens. They will get a loan out to pay or sometimes they just go under. There have been suicides.

"But Mr Roberts challenged this and was right.

"The CSA will point to its computer records, but the computer record is the record of what should have been done, not a record of what has been done."

Mr Roberts warned that problems caused by the CSA "would only get worse" when, if as proposed, it becomes a semi-privatised organisation next year with the authority to confiscate passports and other documents without the need to go through the courts.

A spokesman for the CSA could not confirm any details of the case, but said that the organisation was in touch with Mr Roberts to resolve "any outstanding issues".