Imagine being handed a £24,000 bill for years worth of child support for a daughter you never knew you had.

That's the harsh reality that could be facing shipping clerk Darren Standen, who is now fighting 14 years of administrative muddle by the Child Support Agency (CSA).

Darren, 37, from Wincheap, Canterbury has been married since 1992 and has sons aged five and 13. But the case surrounding him dates back to 1990 and a previous relationship.

He split from that girlfriend after a year together unaware of her pregnancy. She later gave birth and decided not to tell him. Darren remained unaware of his daughter’s existence until 1994, when benefits officers wrote to him with a claim and requested he attended a meeting.

He said: "I went to that meeting in January, 1995, but then I had no contact from the CSA for 10 years. They then tell me that I'm the parent. I re-iterated my desire to have a DNA test, which I first asked for back in 1995. Finally, in 2006, I found out I was the biological father."

Six months later, Darren was told by the CSA the case against him would be dropped.

But that all changed three weeks ago, when a bill for £1,780 arrived on his doorstep, for the first year from 1994.

"My initial reaction was, what are they doing now?" said Darren. "They don’t contact me for 10 years and when they finally contacted me, they tell me I’m in the clear. Two years later, they’re asking for nearly £1,800."

Darren could now face a bill totalling between £22,000 and £24,000 if the CSA decide he is liable for every year since the first claim, but that is dependent on a new assessment of his finances.

"It hasn’t caused anxiety that there is a child," he added. "It’s caused anxiety that there’s been a major mess up that’s not allowed her access to me or to my family. She could have well been part of the family."

The CSA were not able to comment in detail about Mr Standen’s case, but a Department for Work and Pensions spokesman issued a statement.

It said: "When calculating child maintenance payments, the CSA looks at a number of factors to ensure we take into account the individual circumstances of the non-resident parent.

"In cases where child maintenance is not paid, arrears will build up and the CSA will do all it can to track people down and take action."

The statement added: "Although we cannot comment on individual cases, we can confirm we have been in regular contact with Mr Standen for some years."