A friend of the 39-year-old, who has been pictured spending time alone with Martin Kristen since the split, told TMZ that Klum insisted their relationship was "strictly professional" throughout her seven-year marriage.
"It's sad but not surprising that [Seal] would resort to making excuses for their divorce when the real reason is looking him in the mirror," they added, before describing Klum and Kristen's relationship as "very close" but still "undefined".
According to Metro, a representative for the Project Runway presenter also countered Seal's claims and released a statement saying: "It is sad that [he] has to resort to false accusations."
The 'Kiss From A Rose' singer had criticised Klum for "fornicating with the help" and said that her actions proved she "lacked class".
The couple, who have four children together, are still trying to finalise their divorce after failing to agree on the distribution of assets.