Why would that be illegal?
I don't know the law; but claiming to know the whereabouts of the remains of one's loved one - but refusing to reveal this information without payment ... ought to break some law ...
Extortion, Fraud By Wire:
Quoting:
§ 1343. Fraud by wire, radio, or television
Whoever, having devised or intending to devise any scheme or artifice to defraud, or for obtaining money or property by means of false or fraudulent pretenses, representations, or promises, transmits or causes to be transmitted by means of wire, radio, or television communication in interstate or foreign commerce, any writings, signs, signals, pictures, or sounds for the purpose of executing such scheme or artifice, shall be fined under this title or imprisoned not more than 20 years, or both. If the violation occurs in relation to, or involving any benefit authorized, transported, transmitted, transferred, disbursed, or paid in connection with, a presidentially declared major disaster or emergency (as those terms are defined in section 102 of the Robert T. Stafford Disaster Relief and Emergency Assistance Act (42 U.S.C. 5122)), or affects a financial institution, such person shall be fined not more than $1,000,000 or imprisoned not more than 30 years, or both.
Joran Van der Sloot, the longtime suspect in the disappearance of missing Mountain Brook teenager Natalee Holloway, has been accused of offering $250,000 in exchange for her whereabouts.