Robin Thicke owes over $2 million in taxes.

The 'Blurred Lines' singer has reportedly had two Federal tax liens filed against him, and according to The Blast, he owes $1,376,196.97 from the year 2014, and $935,784.06 from 2015, making a grand total of $2,311,784.06.

While it is unclear why Robin hasn't paid his bills, his 2014 album 'Paula' didn't perform as well as expected and in 2015, he and his 'Blurred Lines' collaborator Pharrell Williams were ordered to pay $7.3 million to Marvin Gaye's estate after a jury ruled they had ripped off the singer's track 'Got to Give It Up' for their global hit single.

And the 40-year-old star has been locked in a custody battle with ex-wife Paula Patton over their son Julian, seven, for almost three years until August, when they reached an agreement.

According to the terms of their custody arrangement, Robin - whose girlfriend April Love Geary is pregnant - cares for Julian

Monday through to Wednesday, whilst Paula has him Wednesday through to Friday, with the former couple alternative who takes care of their son over the weekends.

The former couple also agreed to share the cost of expenses, including Julian's private school tuition.

Previously, Robin has spoken of how he and Julian have a very strong bond.

He said: ''We do everything (together). We go to theme parks or museums or ball games or just go to the park on Saturday and sit around and walk for a few hours. Kick a ball and all that stuff that dads and kids do.''

The singer and his model girlfriend are due to welcome their baby into the world on March 1, the birthday of his late father Alan Thicke.