A Nigerian politician has revealed that senators receive 13.5m naira [£27,000, $37,500] every month to use on expenses of their own choice.
Shehu Sani, a senator for the governing All Progressives Congress [APC] party, said there is little accountability about how the money is spent.
He has called for the payments to be scrapped, saying they are a key reason why people choose to enter politics.
"I decided to bust it open. It was a moral issue," Mr Sani told the BBC.
"The National Assembly is one of the most non-transparent organs of government. It pricked my conscience and I decided to burst the bubble and open the National Assembly to public scrutiny."
"If the expenses payment system was ended then parliament would only be attractive to people who contribute ideas," he said.
The money is paid on top of a senator's salary which is more than $2,000 a month. They also receive a yearly constituency budget of $5.5m.
Nigeria's minimum wage, meanwhile, is just $50 a month.
The Senate confirmed Mr Sani's revelation but described it as "nothing new".
"Almost all holders of elective and appointive offices have running costs allocated to their offices that cannot be said to be part of their salaries," a spokesman said.