Cory Monteith has been written out of 'Glee's season finale after checking into rehab.

The 30-year-old actor - who plays Finn Hudson in the comedy-drama show -  'voluntarily' admitted himself into a facility for 'substance addiction' and show bosses have decided to write him out of the finale with his absence explained.

Twentieth Century Fox, which makes 'Glee' has also come out in support for his recent ordeal, releasing a statement saying: 'Cory is a beloved member of the 'Glee' family and we fully support his decision to seek treatment. Everyone at the show wishes him well and looks forward to his return.'

A spokesperson for Cory revealed the actor had taken steps to deal with his addiction by voluntarily admitting himself to a treatment facility.

The representative said: '[Cory] has voluntarily admitted himself to a treatment facility for substance addiction. He graciously asks for your respect and privacy as he takes the necessary steps towards recovery.'

Meanwhile, his fellow Glee cast and crew have come out in support of Monteith in an all out Twitter rampage. Showrunner Ryan Murphy tweeted: 'I am so proud of Cory Monteith and love and support him 100 percent.', while Cory's co-stars also added their support with Kevin McHale writing 'Love you, Cory. So proud of you,' and Jenna Ushkowitz tweeting: 'Sending lots of love and light to Cory. We love you.'

Chris Colfer tweeted, 'Anyone who helps themselves is a hero in my book.' Meanwhile Dot Marie Jones called Cory 'the sweetest man' and warned people not to judge others. She wrote: 'We are - and always will be - here for you. I love you always. Stay strong. You never know what someone is dealing with in their personal life. Don't pass judgement.'

After Cory's admission to rehab was announced, his co-star and girlfriend Lea Michele issued a statement declaring her intention to stand by him.

She said: 'I love and support Cory and will stand by him through this. I am grateful and proud he made this decision.' Lea later tweeted: 'Thank you all so much for all your love, support, and encouragement. It's means the world to us..'