Frank Ocean is being sued over his track 'Lost'.

The singer, his record label Def Jam, and producer Malay are being sued by songwriter Micah Otano, who claims the song is too similar to his composition 'Daylight'.

Micah filed a lawsuit in California last week, seeking compensation for back royalties and damages. In the suit he claims he wrote the track 'Daylight' with Malay, which the producer then copied for 'Lost'.

The track was the fourth single from Frank's breakthrough 'Channel Orange' debut album in the US, which was won a Grammy Award for Best Urban Contemporary Album earlier this year.

Frank has also recently said he is hard at work on the follow up to his highly acclaimed debut and already has a concept and a number of songs ready.

He said: ''I'm 10, 11 songs into this next thing. It's another cohesive thing bordering on a concept album again. At the end of 'Channel Orange' there's 'Golden Girl' and I kind of want to extend that feeling into the next record.''

For his second album Frank is believed to be working with producer Pharrell Williams and rapper Tyler, The Creator among others.