Mr Sants admitted more had to be done
Market abuse in the UK's financial services sector is at an "unacceptably high level", the head of the City watchdog has said.
Hector Sants, the chief executive of the Financial Services Authority (FSA), said more needed to be done to tackle insider dealing and other manipulation.
But speaking to the Sunday Telegraph, he said there was no evidence the UK was worse than other major countries.
He said the FSA would be taking on an extra 460 members of staff.
It is to expand its workforce to 3,700 people.
"Our benchmark should seek to have a market that participants really believe to be clean and fair," said Mr Stants.
"And, as a general test, I think that if you were to ask the market participants, they would share my view that there is too much market abuse."
The FSA will detail the roles of the additional staff when it presents a strategy paper later this week, but it has already said it wishes to become more proactive.
It announced last week that it will start to investigate financial products to ensure they are suitable before they go on sale, rather than focusing in assisting consumers to get redress once problems emerge.
Mr Sants comments come a week after a retired stockbroker was jailed for 21 months after being found guilty of insider dealing.
Malcolm Calvert, a former employee of investment bank Cazenove, used his contacts to get inside information on business deals before getting a friend to buy shares which subsequently went up in value.