The former Gossip Girl star arrived in France on Thursday (21May15) to see her son Hermes, eight, and daughter Helena, five, who were sent to live with their German father, Daniel Giersch, in 2012 after his U.S. work visa was revoked.

Rutherford has been fighting to have her children returned to their native U.S. ever since, and she reveals she has since become embroiled in a new spat with her ex after he demanded she give up Hermes and Helena's travel documents.

Giersch's lawyer claims his client is worried their kids are in danger of being kidnapped after Rutherford went on America's TMZ Live show last week (ends15May15) and declared, "I think that, you know, whoever brings my kids home is going to be pretty much of a hero."

A statement released by Giersch's lawyer, Fahi Takesh Hallin, to, reads: "Any statement to the public suggesting that if someone were to bring the children back to America (which is in violation of the custody orders and criminal) that he or she would be a hero, is unacceptable on many levels. It creates a very real and present risk to the children's safety and well-being that must be taken seriously.

"As a result of such statements by Kelly, Daniel has had to take necessary precautions in accordance with the parties' Judgment and custody orders, which includes requesting that the children's passports be held by a neutral person when the children are not traveling."

However, Rutherford has fired back, insisting she is not willing to give up the legal documents because the "neutral person" in question has not been approved by the U.S. court handling her custody case.

The actress has stepped up her appeal in recent weeks and is now waiting to hear from U.S. President Barack Obama after a White House website petition, calling on the leader to intervene and help bring her children home, attracted more than the required 100,000 signatures for officials to comment on the case.

The former couple split in 2008.