Story highlights Donald Trump Jr.'s meeting in June 2016 with a Russian lawyer has raised eyebrows on the Hill

Sen. Dianne Feinstein, a California Democrat, also wants to hear from Trump Jr

(CNN) The heads of the Senate judiciary committee are writing a letter to Donald Trump Jr. Thursday requesting that he testify before the committee, Chairman Chuck Grassley told CNN.

Grassley, R-Iowa, previewed his intentions Wednesday when he told reporters that he wanted former Trump campaign chairman Paul Manafort to testify before the committee as early as next week, following revelations related to Trump Jr.'s email exchange about meeting with a Russian lawyer regarding potentially damaging information against Hillary Clinton.

"I think it's just raised a lot of questions. but the real way that I feel comfortable inviting him is ever since President Trump was elected," Grassley said Thursday. "It seems like every conversation that has come from somebody in the family where there's been some sort of issue, they've seemed always to be very, very open."

Grassley's comments also come after the top Democrat on the committee, California Sen. Dianne Feinstein told CNN Thursday she wanted Trump Jr. to go before the committee as early as next week. This is the first time a GOP chairman of a committee investigating the Russia issue has publicly acknowledged an effort to bring Donald Trump Jr. before his committee.

Trump Jr. on Tuesday morning posted a series of emails between himself and Rob Goldstone, a music publicist who contacted Trump Jr. and told him about an opportunity to receive potentially damaging information about Clinton as part of a Russian government effort to help his father's campaign. That email led to the June 9, 2016 meeting, at which Trump Jr. later said no meaningful information was provided.

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