All assistance grants made under this chapter shall be reconsidered as frequently as may be required by the rules of the Department to assure continued eligibility. After such further investigation, as the Department may deem necessary, the amount and manner of giving assistance may be changed or the assistance payments shall be terminated if it is found that the recipient's circumstances have altered sufficiently to warrant such action. Assistance payments may at any time be cancelled or revoked or suspended for a temporary period pending further determination if the recipient's eligibility is not clearly established.