A lawsuit filed against a Gaithersburg man suspected in his vacation partner's disappearance in Aruba can move forward, a federal judge has ruled.

Gary Giordano, 51, is suspected in the disappearance of Robyn Gardner, a Frederick woman who vanished in August 2011. He is being sued by the company that issued him an insurance policy covering Gardner's life.

After Gardner went missing, Giordano was detained in Aruba for several months but later released. He has denied any wrongdoing and claims that Gardner was swept away while the two were snorkeling.

Shortly before the vacation, Giordano purchased an insurance policy from AMEX Assurance Company that included $1.5 million in accidental death or dismemberment coverage on Gardner's life. In June, Giordano sued AMEX in a court in Cook County, Ill., seeking to be paid $3.5 million from the insurance policy.

But in September, AMEX filed a lawsuit in federal court in Greenbelt, asking that the accidental death coverage under the policy be voided.

That lawsuit claimed that Giordano didn't have an insurable interest in Gardner's life because they weren't related, married, involved in business together or joint property-owners. It also argued that Giordano engaged in fraud when he named Gardner as his "partner" on the policy because Giordano has described the pair's relationship as casual and nonexclusive.

Giordano filed a motion to dismiss AMEX's lawsuit in October. He argued that the lawsuit should be dismissed because his lawsuit in Illinois involves the same parties and the same issues. He also argued that AMEX's complaint "consists of bare legal conclusions unsupported by factual allegations."

But in his ruling last week, Judge Alexander Williams refuted Giordano's claims.

Although Williams acknowledged that the two lawsuits both have the same parties, he stated that the issues presented in the two lawsuits are different. Giordano's lawsuit in Illinois assumes that the insurance policy is enforceable, but AMEX's lawsuit questions the policy's validity.

Additionally, Williams wrote in his ruling that AMEX's complaint is not too general and adequately presents enough facts to claim a need for relief.