The 25-year-old was told by The Hatters that there was no money available to sign him and the Lens custodian has since left Kenilworth Road following the completion of his two-month loan spell.
The news comes after manager Joe Kinnear was told at a board meeting that there is no money available to sign any more players - including on loan - unless Luton sell players first.
Kinnear told the Luton Town official website: "I was told yesterday that there is no money to sign Berthelin, so he has to go home this morning.
"It would have cost £20,000 to keep him but the board say they're skint.
"I was shocked to find that's the state we're in.
"For me to bring in any players, I'd have to sell some of our best players, which I don't want to do.
"I don't want to sell (Steve) Howard or (Matthew) Spring. That wouldn't make us stronger. No one's for sale.
"I'm not even in a position to get loans in, so we just have to get on with what we've got.
"I put a sensible case to the board, but the answer is that if we haven't got any money, we can't do anything.
"Cedric has done extremely well since he's been here and I think that someone will snap him up in five minutes.
"But it's not to be. We can't keep three goalkeepers even though it would have cost a thousand a week to keep him on."
Meanwhile, Luton Town have signed striker Steve Howard to a two-year contract extension that will keep him at the club until June 2005.
The 26-year-old won the Division Three Golden Boot last season after he scored 24 goals in helping The Hatters to winning promotion.
Howard has already hit double figures with his goal-scoring this season and Kinnear will be delighted to have tied Howard down to a longer deal.
