Kristen Stewart admits to affair with married director

Robert Pattinson and Kristen Stewart

Twilight star Kristen Stewart has publicly apologised for an affair she had with a married man.

The 22-year-old has been in a relationship with co-star Robert Pattinson for around three years.

"I'm deeply sorry for the hurt and embarrassment I've caused to those close to me," she told People Magazine.

"This momentary indiscretion has jeopardized the most important thing in my life, the person I love the most, Rob. I love him, I'm so sorry."

Kristen Stewart and Rupert Sanders
Kristen Stewart and Rupert Sanders worked together on Snow White

There has been no comment yet from 26-year-old British actor Robert Pattinson.

Reports had suggested that Kristen Stewart had had an affair with director Rupert Sanders, who she worked with on Snow White and the Huntsman.

Sanders is married to model and actress Liberty Ross, 33, and the couple have two children.

Liberty Ross played Kristen Stewart's mother in Snow White and the Huntsman.

British director Rupert Sanders has also released a statement.

"I am utterly distraught about the pain I have caused my family," it said.

"My beautiful wife and heavenly children are all I have in this world. I love them with all my heart.

"I am praying that we can get through this together."

Kristen Stewart and Robert Pattinson are due to start a promotional tour together for the final instalment of the Twilight franchise, Breaking Dawn: Part 2.

Breaking Dawn: Part 2 is released in UK cinemas this November.