Twitter says Jamal Khashoggi has subscribed to its Blue service
The blue tick, which officially needs to be paid for, was added to Khashoggi's account on Saturday, as well as accounts previously belonging to Anthony Bourdain, Chadwick Boseman, Pele and Terry Pratchett, all of whom have died.
When users click on the tick icon next to their names, a window appears saying: "This account is verified because they are subscribed to Twitter Blue and verified their phone number."
Khashoggi, a former columnist for Middle East Eye and the Washington Post, was killed in the Saudi consulate in Istanbul in 2018 in an assassination that American intelligence services believe was approved by Crown Prince Mohammed bin Salman, though he denies this.
"This is obscene," tweeted journalism professor Mohamad Bazzi.
TV pundit and commentator Keith Olbermann hit out at Twitter owner Elon Musk for the decision. Musk, CEO of SpaceX, purchased Twitter last year after a long-running legal and financial battle that saw him attempt to withdraw from the deal.
"Here's the problem with putting an impulsive clod who has clinical trouble processing reality in charge of twitter," Olbermann wrote.
"It ends up with him claiming the assassinated Jamal Khashoggi has just purchased 'Twitter Blue'."
Although Twitter verification was previously given on the basis of being able to prove your identity, and could be applied for, since taking over Twitter, Musk has removed the blue tick from those previously verified and officially requires a user to pay an $8 monthly subscription for the status.
However, a number of high-profile figures have found themselves with blue ticks on their accounts despite not having paid the subscription fee.
"My Twitter account says I've subscribed to Twitter Blue. I haven't," wrote author Stephen King.
"My Twitter account says I've given a phone number. I haven't."
Many users have been spreading the #BlockTheBlue hashtag in response, calling for all users who have purchased verification to be blocked.
Some of those who posted the #BlockTheBlue hashtag appeared to then receive blue ticks from Twitter.
The popular surreal humour account and "shitposter" Dril, who has over a million followers on Twitter, received a blue tick on Saturday after posting the hashtag. After it was pointed out that changing his username removed the verification, he changed his Twitter name, removing the verification.
However, it appears Twitter again handed him verification, causing him to again change his name. This happened several times, but as of Sunday morning - and with his username as "slave to Woke" - Twitter seems to have given up.