The brothers had been due to stand trial accused of Mr Parsons’ murder, but Sandy McKellar pled guilty to the reduced charge of culpable homicide at the High Court in Glasgow in 2023.
His brother had his not guilty plea to murder accepted.
The pair both admitted attempting to defeat the ends of justice.
Sandy McKellar was jailed for 12 years and his brother Robert was jailed for five years and three months.
Mr Parsons’ family previously said that not knowing what happened to the 63-year-old had taken its toll on the family.
In a statement read out in court in 2023, they described him as “a much-loved husband, dad and grandad”.
They said: “When he said goodbye and set off on his charity cycle from Fort William that Friday, none of us expected it to be the last time we would be able to see or speak to him.
“Throughout the six years since he went missing and then the subsequent criminal investigation, we had been left with many unanswered questions and it has been heart-breaking for each and every member of the family being unable to get these answers.
“As you can imagine, not knowing what has happened to someone and then the devastating news that we were provided has taken its toll on all of us as a family.”
