Massachusetts regulators have charged Securities America, a broker owned by Ameriprise Financial Inc., with selling $697 million in investments without fully warning investors about the risks involved.

The promissory notes were issued by companies owned by Medical Capital Holdings Inc., which ended up defaulting on $1 billion in obligations in August 2008. Medical Capital is under investigation by the Securities and Exchange Commission for fraud.

Secretary of State William F. Galvin yesterday charged Securities America because he said it placed more than one-third of Medical Capital’s $1.7 billion in notes. That includes $7.2 million in notes sold to 60 Massachusetts investors. Galvin said Medical Capital paid Securities America $26 million in compensation and funded trips for Securities America executives, including vacations at Las Vegas resorts and golfing outings to Pebble Beach in California.

“People invested their life savings, while this dealer hid from them the truth of what they were getting into,’’ Galvin said in a statement. He wants Securities America to reimburse Massachusetts investors for their Medical Capital holdings.

A spokeswoman for Securities America, Janine Wertheim, said Galvin’s complaint contained “inaccuracies.’’

“We take the safety and security of our clients very seriously and make risk management a cornerstone of our business,’’ Wertheim said. “Securities America conducted considerable due diligence and met all industry standards for such due diligence. Fifty or more other broker dealers independently conducted due diligence, did not detect the alleged fraud committed by Medical Capital, and approved and sold the Medical Capital notes.’’

On Aug. 3, 2009, the SEC obtained an emergency order halting an offering of $77 million by Medical Capital, alleging the company was perpetuating a fraud.

(By Todd Wallack, Globe Staff)