Republican senators on Sunday threw cold water on Saudi Arabia’s shifting explanations for journalist Jamal Khashoggi’s death, calling for significant action to be taken against the kingdom if the Saudi crown prince is found responsible.

Saudi Arabia, which initially denied any involvement in Khashoggi’s Oct. 2 disappearance, claimed last week that The Washington Post columnist had been strangled in a fistfight with 15 men sent to confront him at the Saudi consulate in Turkey.

But Sen. Bob Corker (R-Tenn.), during an appearance Sunday on CNN’s “State of the Union,” said Saudi Arabia had “lost all credibility as it relates to explaining what happened” to Khashoggi.

“I don’t think anybody believes that story,” said Corker, chairman of the Senate Foreign Relations Committee. “It’s just not credible.”

Corker, who met with Secretary of State Mike Pompeo on Saturday, told CNN that he believes Saudi Crown Prince Mohammed bin Salman, who is often referred to as MBS, was involved in Khashoggi’s killing.

“Obviously, if [MBS] has gone forth and murdered this journalist, he’s now crossed the line, and there has to be a punishment and a price paid for that,” Corker said. “Do I think he did it? Yeah. I think he did it.”

.@SenBobCorker on the Crown Prince: "Obviously if he's gone forth and murdered this journalist, he's now crossed the line, and there has to be a punishment and a price to pay for that... Do I think he did it? Yeah. I think he did it." #CNNSOTU pic.twitter.com/aHbGTv98nI — State of the Union (@CNNSotu) October 21, 2018

Saudi Arabia on Saturday blamed some of the crown prince’s inner circle for Khashoggi’s death. Five high-ranking officials, including a former two-star general and the communications chief for MBS, were dismissed, and 18 others were detained.

President Donald Trump has been reluctant to blame Saudi Arabia’s leadership for the death of Khashoggi, a high-profile critic of the crown prince. On Friday, Trump said he found Saudi Arabia’s account credible and that the new information was “a good first step.”

Trump offered his first public criticism of Saudi Arabia’s account of Khashoggi’s death in an interview Saturday with The Washington Post, saying there had been “lies” and “deception.” But the president was also quick to praise the crown prince as a “strong person” and called Saudi Arabia an “incredible ally.” He said the journalist’s death shouldn’t get in the way of a major arms deal between the two countries.

But Sen. Rand Paul (R-Ky.) on Sunday urged Trump to end U.S. arms sales to Saudi Arabia, calling the kingdom’s Khashoggi claims “insulting.”

“I think it stretches credulity to believe that the crown prince wasn’t involved in this,” Paul told “Fox News Sunday.” “There’s no way 15 people were sent from Saudi Arabia to Turkey to kill a dissident without the approval of the crown prince.”

He continued: “That’s why I say we have to be stronger than just saying, ‘Oh, we’re going to sanction a few of these people and pretend like we’re doing something.’ I think we really need to discontinue our arms sales to Saudi Arabia and have a long and serious discussion about whether they want to be an ally or they want to be an enemy.”

.@RandPaul tells Chris: “There’s no way 15 people were sent from Saudi Arabia to Turkey to kill a dissident without the approval of the Crown Prince.” #FNS pic.twitter.com/F23CBMhzIq — FoxNewsSunday (@FoxNewsSunday) October 21, 2018

Khashoggi entered the Saudi consulate in Instanbul on Oct. 2 to obtain paperwork needed for his upcoming wedding. His fiancee waited outside, but he never reappeared. Turkish officials contend the journalist was killed and dismembered by Saudi nationals within hours after he stepped inside.

Like Paul, Sen. Ben Sasse (R-Neb.) suggested a viable next step for the U.S. would be to rethink its arms sales with Saudi Arabia in light of Khashoggi’s death.

“We don’t do arms sales for the purpose of the profits from arms sales ― we do arm sales because we want to be aligned with different countries around the globe that believe in our values,” Sasse told CNN following Corker’s interview.

“I think the cover stories from the Saudis are a mess,” he continued. “You don’t bring a bone saw to an accidental fistfight. ... The Saudis have said a whole bunch of crap that’s not right, accurate or true.”

"You don't bring a bone saw to an accidental fist fight," says GOP Sen. Ben Sasse of the Saudis' explanation for journalist Jamal Khashoggi's death. "The Saudis have said a whole bunch of crap that's not right, accurate, or true" #CNNSOTU pic.twitter.com/kplFCzD1nU — CNN Politics (@CNNPolitics) October 21, 2018

Sen. Thom Tillis (R- N.C.) echoed his fellow Republican lawmakers on Sunday, telling NBC’s “Meet the Press” that he did not think any part of the Saudi government’s explanation was credible.

Despite Trump’s hesitation to speak out against the Saudi royal family, Tillis said he believes “the president will take the appropriate action when all the facts are in.”

Former House Speaker Newt Gingrich (R-Ga.), one of Trump’s most outspoken supporters, told “Fox News Sunday” that Saudi Arabia’s story is “insultingly stupid.”

“On the one hand you don’t want to break the alliance with the Saudis,” Gingrich said. “On the other hand you cannot teach a 33-year-old crown prince that he can get away with things that are this outrageous and stupid or he will be out of control for the next 40 years.”

On the other side of the aisle, Democratic lawmakers have almost universally called into question Saudi Arabia’s explanation for Khashoggi’s death.

Sen. Dick Durbin (D-Ill.) told “Meet the Press” on Sunday that the U.S. should expel the Saudi ambassador from the U.S. while a third-party investigation is conducted into “this kidnap, murder and God-knows-what followed.”