Tulisa Contostavlos has been arrested on suspicion of supplying class A drugs.
The former X Factor judge was taken into police custody following a Sun undercover sting in which she was allegedly recorded setting up a deal for cocaine worth £800.
A Metropolitan Police spokesperson said: "Officers from Westminster have arrested two people - a 35-year-old man and a 24-year-old woman - on suspicion of supplying class-A drugs.
The arrest comes hours after investigators confirmed that they had "received information concerning the alleged supply of illegal drugs at a central London location".
A story published in the tabloid claimed that Contostavlos acted as a fixer by introducing a journalist to an alleged supplier.
According to the Sun, half an ounce of cocaine changed hands in a deal at London's Dorchester Hotel.
Contostavlos was recently replaced by Sharon Osborne as a judge on ITV's The X Factor.
A spokesman for Contostavlos declined to comment on the arrest and police confirmed she has since been bailed.
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