A dance track titled Somebody Else was released online last week with vocals uncannily like Ms Allen's set to a backing track in the style of the British DJ Fred Again.
The singer, 39, returned to work on her Miss Me? podcast on Thursday after she checked into the facility and told friends she was close to a nervous breakdown amid the couple's split.
EXCLUSIVE: David Harbour is said to be dating 27-year-old Ellie Fallon, who he is thought to have known for several months, after calling time on his marriage to Lily Allen in December.
The singer, 39, shocked her fans when she launched an account on to the adult subscription site to sell pictures and videos of her feet in July last year - under the title 'Lily Allen FTSE500'.
In her first podcast episode back after her stint in the centre, she admitted she didn't want her children to 'have to prop her up' as she battled 'emotional turmoil' following her split.
Kirsty Allen, 31, hit another woman in the face with a hammer in a vicious attack after she heard her boyfriend had been cheating on her while she was pregnant.