Authorities continue to search for answers regarding Dr. Michael Mosley's unexpected death. 

One day after the former BBC medical journalist was found dead following a four-day search on the Greek island of Symi, the post-mortem has determined he has died from natural causes. 

During an initial autopsy, authorities found no injuries on his body that could have caused his death, Greek Police spokesperson Konstantia Dimoglidou informed BBC News. Further, the position his body was found in, which was lying face up, determined he succumbed to natural causes. It was also determined that Michael's time of death was around 4 p.m. on June 5, the same day his wife Dr. Clare Mosley—who accompanied him on the trip to Greece—reported him missing. 

A toxicology report and histology report have now been ordered for the 67-year-old, Greek police also told BBC. 

On June 5, Michael separated from his wife during the couple's vacation to take a short hike at around 1:30 p.m. local time. When he did not return hours later, his wife raised concern, sparking an island-wide search.

He was found June 9 near a fence by an island bar, and his wife determined he had taken the wrong route during his hike. 

"He did an incredible climb," she noted. "And collapsed where he couldn't be easily seen by the extensive search team."

After his body was discovered, Michael's wife paid tribute to her late husband and shared gratitude for the people who sent support or assisted in his search. 

"It's devastating to have lost Michael, my wonderful, funny, kind and brilliant husband," Clare said in a statement to People June 10. "We had an incredibly lucky life together. We loved each other very much and were so happy together."

The health columnist—who shares adult children Alex, Jack, Dan and Kate with the late journalist—continued. "My family and I have been hugely comforted by the outpouring of love from people from around the world."