Del. Code Ann. tit. 9, § 2605
At any public hearing held pursuant to this subchapter, the Department of Land Use may summon witnesses, administer oaths and compel the giving of testimony.
48 Del. Laws, c. 321, § 6; 9 Del. C. 1953, § 2609; 55 Del. Laws, c. 85, § 18B; 66 Del. Laws, c. 207, § 1; 71 Del. Laws, c. 401, § 85