Twins born to musician Etheridge

Etheridge (r) held a commitment ceremony with Ms Michaels in 2003

US singer Melissa Etheridge and her partner Tammy Lynn Michaels have become parents to twins.

A boy and a girl were born to Michaels and are in "excellent health", the singer wrote on her website.

The children were conceived using an anonymous donor from a sperm bank. Their son has been named Miller Steven and their daughter Johnnie Rose.

The couple held a commitment ceremony in 2003. Etheridge has two children from a previous relationship.

The 45-year-old Grammy winner's daughter and son with former partner Julie Cypher were conceived through artificial insemination with a sperm donation from rock musician David Crosby.

Etheridge was diagnosed with breast cancer in 2004 but was declared to be in full remission nine months after treatment.

Her last release was a greatest hits compilation entitled The Road Less Travelled, and she has sold more than 25m records around the world.