Kessler Twins Paid More Than $6,900 for Their Assisted Suicides

The Kessler Twins paid thousands for their assisted suicides ... TMZ has learned.

Wega Wetzel -- a spokesperson for the assisted suicide company DGHS -- tells TMZ ... the going rate for one assisted suicide is 4,000 euros per person, or 6,000 euros for two people together -- that's about $4,600 and $7,000, respectively. This covers the cost of complete care by doctors and lawyers, including expenses.

Alice and Ellen Kessler contacted DGHS -- which, when translated, stands for German Society for Humane Dying -- more than a year ago because they wanted to end their lives with dignity on the same day together, Wetzel says. They ultimately decided to end their lives in their home in Grünwald near Munich this week.

We asked Wetzel to give us the rundown of the process ... explaining a physician brings an infusion -- an overdose of anesthetic -- and inserts the patient with the infusion needle. The patients themselves have to open the infusion. Once the client is dead, DGHS informs the police. The company mediated more than 600 cases of assisted suicide last year.

This isn't a decision made on a whim, BTW ... according to the company website, candidates must have a membership with DGHS for a minimum of 6 months, submit an application for placement, and meet for multiple consultations with lawyers, doctors and possibly relatives prior to the assisted suicide.

The Kesslers were a world-famous singing duo who performed with the likes of Dean Martin, Frank Sinatra and Fred Astaire.

Alice and Ellen were 89.

RIP