Image caption Fake Rothko paintings were included - these originals are at the Mark Rothko museum in Latvia

A New York art dealer has pleaded guilty to being involved in a 15-year multi-million dollar art fraud.

Glafira Rosales admitted she defrauded two Manhattan art galleries of more than $30m (£18m) with 63 fake art pieces.

The paintings were said to be never-before-exhibited and previously unknown works of art by artists including Jackson Pollock and Mark Rothko.

They were sold to unsuspecting buyers for more than $80m (£50m).

Rosales pleaded guilty to nine charges including wire fraud, tax fraud and money laundering.

She admitted in court that the works of art "were actually fakes created by an individual residing in Queens''.

The artist who painted the fakes, 73-year-old Pei-Shen Qian, won't be charged and has returned to his native China, prosecutors said.

Rosales earned millions selling counterfeits to the Knoedler Gallery and Julian Weissman Fine Art in Manhattan.

As part of a plea deal, she was told she must forfeit $33m (£20m), and restitution in an amount up to $81m (£50m) that has yet-to-be-decided.

She also must give up her home in Long Island and art she purchased between 1994 and 2012.

However, the deal also stated prosecutors promise not to bring charges related to further crimes including a fraudulent marriage between Mexican-born Rosales and a US citizen.

Rosales will be sentenced in March and prosecutors say more people will be charged in the art fraud case.