Lewis, who married Baskin in 1991, disappeared in 1997 and was declared dead five years later.
No evidence of him being murdered has emerged, but the case into his disappearance was reopened this year after it featured in the Netflix docuseries about GW Zoo owner Joe Exotic, who is currently serving a 22-year prison sentence.
In Tiger King, Exotic made claims that his rival, Big Cat Rescue CEO Baskin, killed her husband and fed him to her tigers.
Baskin has always strongly denied any involvement in Lewis’s disappearance.
A new documentary, Joe Exotic: Tigers, Lies & Cover-Up, follows retired police officer Jim Rathmann and his investigation into Lewis’s disappearance.
Carole Baskin starred in Netflix’s Tiger King (Picture: MEGA)
Lewis was due to fly to Costa Rica the weekend he disappeared, with his mechanic Dale Lively attesting to this in the documentary.
Following up on a theory about Lewis crashing his private aeroplane in Costa Rica, where he often travelled to look for deals on wild cats, Rathmann visited his lawyer, Joe Fritz.
Fritz claimed Lewis was murdered, saying in the documentary: ‘I had heard that he got strangled with an electric cord from the backseat of his airplane. With somebody else flying, he got dumped out over the gulf.
‘I heard it from two different sources. It kind of fits the scenario, because he was a pilot, he’d owned planes, he had a license, he lost his licence. His van is at Country Pilot Estates. It’s an unmanned airport, nobody logs you in, nobody logs you out. It’s not unusual for somebody to take off in a plane. So, it all fits together.’
Fritz claimed that Lewis was lured onto the aeroplane with a business deal, before being ejected from it mid-flight.
‘He got lured up there to do a great deal on an airplane,’ he alleged. ‘He showed up.
‘Our Sheriff says there was more than one person involved. Yes, he’s right. There’s no question in my mind that this was a murder. The question is who did it and who is behind it?’
Rashmann went on to question Fritz’s claims, asking: ‘Is it even possible to throw somebody out in flight?
‘If you had to open that door going against 120, 140 knots, and trying to force that door open and push out a person that you would say at least weighed 150, 160lbs, that would have been very challenging.’
During his investigation, Rashmann also followed up on the allegations that Baskin was involved in Lewis’s disappearance.
Lewis disappeared in 1997
He said: ‘The person who had the most to gain would have been Carole. She now was able to collect all of Don’s property, she put herself as head of all the trusts, and she made millions upon millions of dollars from that.’
He also brought in a handwriting expert to analyse Lewis’s will.
Forensic handwriting expert Thomas Vastrick strongly suggested that Lewis’s signature was forged, saying: ‘When I looked at Mr Lewis’s signature on both his last will and testament and the durable family power of attorney, I noticed that the signatures were too similar to be normal.
‘If you write your name 10 times, or even just two times, you’ll notice differences between each signature, it’s called natural variation. I noticed in these a lack of variants, and that to me, in my opinion, is a tell-tale sign of an attempt to trace.’
On the section of her Big Cat Rescue website where she responds in detail to the Tiger King series, Baskin says that all documents relating to the will were ‘authenticated by multiple firms and stipulated to be authentic by all parties to the conservatorship, including Don’s daughters.’
In the documentary, Rashmann also speaks to a former partner of Baskin’s, Alan Schreier, who said he is ‘on the fence’ about the allegations of her being involved in Baskin’s disappearance.
He said: ‘She did not care for my son or for people. I knew from the get-go, Carole doesn’t like people, Carole likes cats,’ he says.
Asked if he thought that Baskin could have been involved with the disappearance, he added: ‘When I first met her the answer was 99.9 per cent sure that she didn’t do it. Now I’m 50/50.
‘I really believe in my heart that she forged the will and some other things.’
Baskin previously recalled her memory of the day her husband went missing for the Dateline documentary What Happened to Don Lewis?
She said: ‘My husband left early in the morning and said that he wanted me to get a truck ready, that he was gonna be driving down to Miami to put on the freight cargo down to Costa Rica the next day.
‘When he didn’t come home the rest of the night, then we turned him in as a missing person. And we haven’t seen or heard anything since then.’
Joe Exotic: Tigers, Lies & Cover-Up is available to stream now on discovery+.
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