A transcript of a threatening voicemail that Miami Dolphins offensive lineman Richie Incognito allegedly sent to Jonathan Martin reveals that the suspended player directed racial slurs and threats at his teammate.

Sources close to the situation reportedly confirmed that Incognito left a racially charged, threatening voicemail for Martin in April 2013, ESPN’s Adam Schefter reports. In the voicemail, the 30-year-old lineman refers to Martin as a “half n-----" before claiming he would physically assault him.

“Hey, wassaup, you half n----- piece of s---. I saw you on Twitter, you been training 10 weeks. [I want to] s--- in your f------ mouth. [I’m going to] slap your f------ mouth. [I’m going to] slap your real mother across the face [laughter]. F--- you, you’re still a rookie. I’ll kill you,” the voicemail transcript read.

Officials from both the NFL and the Dolphins' front office have reportedly listened to the voicemail, ESPN reports. There are multiple copies of the recording.

Sources familiar with the situation claim Incognito regularly used the sort of language heard in the voicemail when conversing with Martin. According to ESPN's report, he routinely used racial slurs and made derogatory insinuations about Martin’s sexual orientation.

Schefter’s report corroborates a previous report by CBS Sports’ Jason La Canfora, who reported Monday morning that Incognito had threatened to harm Martin and members of his family.

On Sunday, the Dolphins announced in a statement that Incognito would be suspended indefinitely for conduct detrimental to the team. "We believe in maintaining a culture of respect for one another, and as a result we believe this decision is in the best interest of the organization at this time. As we noted earlier, we reached out to the NFL to conduct an objective and thorough review. We will continue to work with the league on this matter," the statement read.

Incognito maintained his innocence as recently as Sunday, despite reports of his direct involvement in bullying that caused Martin to leave the Dolphins and check himself into a hospital for counseling. The Dolphins offensive lineman went on a Twitter rant over the weekend, bashing Schefter, ESPN and various other media outlets for their handling of the Martin story.

“Stop slandering my name," Incognito wrote in a tweet addressed to Schefter. “You hide behind ‘sources’ who are not man enough to put their name behind the BS you report. This is the second time you have tried to drag my name through the mud with [sic] lies.”