Fairfax Media has been told the woman was transferred to Perth earlier this year but discharged from hospital and sent back to Christmas Island against the advice.

It is believed the woman, who was not a mother on the island, tried to take her own life this week and remains in Christmas Island Hospital.

Sources have told Fairfax Media a number of asylum seekers continue to be held on Christmas Island despite advice that they be transferred to Australia to be treated for mental illnesses. ''This is not manipulation [of the system],'' a source said. ''It's widespread and it's getting worse.''

It comes as Christmas Island Shire President Gordon Thomson said the number of asylum seekers on suicide watch had increased from 11 on Wednesday to 14 on Thursday.

''They are on constant watch,'' he said.

Immigration Minister Scott Morrison this week denied Fairfax Media reports that up to nine women had attempted suicide, saying multiple suicide attempts by women on Christmas Island were ''not correct''.

Mr Morrison has refused to provide information on self harm in detention, citing privacy and the risk of copycat behaviour.

On Wednesday, Fairfax Media obtained advice from the Department of Immigration showing that following a meeting on Christmas Island this week, there were ''seven individuals who made threats of self harm, four have actually self harmed, and one woman attempted suicide''.

But an International Health and Medical Service employee said the categories of ''self harm'' and ''attempted suicide'' were often hard to differentiate.

Royal Australian and New Zealand College of Psychiatrists president Dr Murray Patton said it was not surprising to hear of reports that women on Christmas Island were harming themselves.

''The college is extremely concerned that people are finding themselves in such a desperate situation that they are considering such measures as attempting suicide,'' Dr Patton said.

Senator Eric Abetz described the incidents on Monday night as ''minor self harm''. But Greens senator and immigration spokeswoman Sarah Hanson-Young said that response was ''callous and insincere''.

''Suicide attempts are not 'minor incidents', as so ignorantly described by the Abbott government,'' she said. ''The Department of Immigration's own contract with Serco defines attempted serious self harm as a critical incident.''

The Department of Immigration declined to comment on the specifics of the case.

"The Department of Immigration and Border Protection is advised by its contracted health services provider, IHMS, regarding appropriate placement of detainees with health issues," it told Fairfax Media.

"On Christmas Island, health care and support, including mental health care, is provided onsite by medical practitioners, mental health nurses, psychologists, counsellors and visiting psychiatrists.

"For privacy reasons, it is not appropriate for the Minister to comment on a person’s individual circumstances.

"It is longstanding government practice not to confirm or comment on reports of individual acts of self-harm."

For help call SuicideLine on 1300 651 251 or Lifeline on 131 114, or visit beyondblue.org.au.