A Chicago police officer has been found dead in the same home where her cop husband died of a mysterious suicide two years ago.

Dina Markham, 47, is believed to have killed herself after she was found unresponsive in a bathtub in the family home after ingesting pills on Sunday.

The medical examiner's office has not officially ruled on a cause of death, but police are investigating it as an apparent suicide.

Her death comes after the FBI, at the request of Chicago Police, started recently re-examining the apparent suicide of her 51-year-old husband Donald Markham, the Chicago Sun Times reports.

Dina Markham, 47, was found dead in her Chicago home on Sunday in an apparent suicide. It comes two years after her police officer husband Donald Markham died in a mysterious suicide

Some officers had raised concerns about the way evidence was collected at the scene when Donald was found with a gunshot wound to his head in the couple's home in September 2015.

It's not exactly clear what prompted the new probe. According to the Chicago Sun Times, the investigations have been ongoing for several months. A February 21 subpoena was sought about Donald's death from the medical examiner's office.

A Sun Times reporter had contacted Dina for comment about the new probe in the days before her death.

On May 22, she said she was 'unaware of the new investigation, would like to speak but needed a day to process it'. Then two days later when approached again, she told the publication she needed to 'protect herself and her children'.

A day later she emailed the publication saying: 'In respect for the way you approached me, a friend of a friend will be in contact with you. I am unsure who that will be at this time, but he assured me he will follow through.

'My family and I have been through very difficult times, and it has been awful especially for my children. Should you proceed in writing a news story, I would appreciate a 'heads-up' to prepare them.'

Her death comes after the FBI started recently re-examining the apparent suicide of her 51-year-old husband Donald Markham who was found with a gunshot wound to his head in the couple's family home

Police reports from the time of Donald's death showed the narcotics officer had killed himself after drunkenly arguing with his wife at a bar and later at their home.

Dina is believed to have killed herself after she was found unresponsive in a bathtub in the family home after ingesting pills on Sunday

Dina had told police she was initially locked out of the house and found her husband dead in their bed when one of their children let her into the home.

Police reports indicate Dina then called 911.

The detective investigating Donald's death that night wrote in his report that the gun belonged to the dead cop but it was not his service weapon.

He also wrote that the death was a suicide and no foul play was suspected.

The medical examiner's office were unable to conduct their own investigation or examine the scene because they weren't notified of Donald's death until hours later.

The officer's body had already been removed from the home and was being transported to the morgue when the medical examiner's office were told, which is against standard practice.

'There was no history of suicidal ideations or suicide attempts and no suicide note was found on scene,' the medical examiner's report said.

Dina and Donald, both Chicago cops, were married in 1995 and had five children together

Donald and Dina were married in 1995 and had five children together. Dina is pictured above with some of her children

Donald's death was ruled a suicide after a medical examiner conducted an autopsy.

Investigators now want to know if Donald was killed, if police somehow mishandled the investigation or if officers were involved in a cover-up.

As well as removing Donald's body from the scene before it was examined by the medical examiner, there are concerns that no one tested his wife for gunshot residue to rule out whether she fired the gun.

The couple were married in 1995 and had five children together.

Denis P. Walsh, the lieutenant in charge of supervising the investigation into Donald's death, was accused three months later of mishandling a murder case he was looking after.

Steps were taken to fire him after Walsh admitted to keeping missing files at his home, but he resigned himself in February 2016.

For readers seeking help, please contact the National Suicide Prevention Line on 1-800-273-8255 or visit the website.